Respiratory System

Question 1

What is the respiratory system?

Answer 1

Series of organs responsible for taking in oxygen and expelling carbon dioxide.

Question 2

Describe the pathway of air

Answer 2

1. Nasal cavity and mouth
2. Trachea
3. Left or right bronchi
4. Bronchioles
5. Alveoli
6. Gaseous exchange

Question 3

Describe the function and/or characteristics of the trachea

Answer 3

Function - Tube carrying air to the lungs.

Characteristics - Made up of rings of cartilage to prevent it from collapsing. C-shaped rings to allow for expansion and contraction during inhalation and exhalation.

Question 4

Describe the function and/or characteristics of the bronchi

Answer 4

Characteristics - First branch from trachea. One bronchus leads to each lung.

Question 5

Describe the function and/or characteristics of the bronchioles

Answer 5

Characteristic - Bronchi branch off into bronchioles which lead into the alveolus.

Question 6

Describe the function and/or characteristics of the alveoli

Answer 6

Function - Where gaseous exchange occurs.

Characteristics - Air sacs. Millions of alveoli in each lung, presenting a large, moist surface area for gaseous exchange. Surrounded by blood capillaries.

Question 7

Describe the function and/or characteristics of the diaphragm

Answer 7

Function - Contracts and relaxes to allow for inhalation and exhalation.

Characteristics - Sheet of muscle at the base of the chest cavity dividing it from the abdomen.

Question 8

Describe the function and/or characteristics of the intercostal muscles

Answer 8

Function - Raise and lower the ribs upon contraction and relaxation.

Characteristics - Muscles between the ribs, they are a skeletal muscle.

Question 9

Describe the pathway of oxygen into the capillaries

Answer 9

1. O₂ enters respiratory system through the nasal cavity and mouth.
2. Travels down the trachea, dividing into the left and right bronchi.
3. The airways narrow and branch off into bronchioles.
4. O₂ reaches the alveoli where gaseous exchange occurs with the capillaries.

Question 10

Define GASEOUS EXCHANGE

Answer 10

The process in the lungs whereby O₂ is delivered to the bloodstream, while CO₂ is removed from it. Takes place in the alveoli.

Question 11

How can gaseous exchange be maximised? (4 marks)

Answer 11

1. Millions of alveoli in lungs, providing a large, moist surface area for gaseous exchange to take place.
2. Each individual alveolus is surrounded by bloody capillaries which ensures a good blood supply.
3. The walls of the capillaries are only 1 cell thick, which gaseous exchange more efficient.
4. Alveoli are well ventilated - air can reach them easily.

Question 12

Describe how gaseous exchange occurs at the alveoli

Answer 12

1. O₂ arrives at alveoli after inhalation.
2. Deoxygenated blood arrives at the alveoli via capillaries, CO₂ diffuses from the capillaries into the alveoli.
3. O₂ diffuses from the alveoli into the capillaries to oxygenate the blood.
4. CO₂ is exhaled.

Question 13

Describe the mechanics of inspiration. (Diaphragm and intercostal muscles)

Answer 13

1. Diaphragm contracts and flattens.
2. Intercostal muscles contract and expand the chest cavity up and out, increasing the volume.
3. The expansion lowers the pressure in the chest below the pressure of the outside air.
4. Air flows into the lungs as it moved from a high pressure (outside air) to a low pressure (lungs).

Question 14

Describe the mechanics of expiration. (Diaphragm and intercostal muscles)

Answer 14

1. Diaphragm relaxes and domes.
2. Intercostal muscles relax and the chest cavity volume decreases.
3. The decrease in chest cavity volume results in an increased pressure in the chest cavity - higher than the outside air pressure.
4. Air moves from the lungs as air moves from a high pressure (lungs) to a low pressure (outside air).

Question 15

Define TIDAL VOLUME

Answer 15

Volume of air inhaled in one breath during normal breathing.

Question 16

Define RESPIRATORY/BREATHING RATE

Answer 16

Number of breaths taken in one minute.

Question 17

Define MINUTE VENTILATION/VOLUME

Answer 17

The volume of air, in litres, breathed in in one minute.

(Tidal Volume x Respiratory Rate = Minute Ventilation)

Question 18

Define VITAL CAPACITY

Answer 18

The maximum volume of air you can breathe out after a maximal inhalation.

Question 19

Define RESIDUAL VOLUME

Answer 19

The volume of air left in your lungs after breathing out. This remaining air prevents our lungs from collapsing.

Question 20

Define TOTAL LUNG CAPACITY.

Answer 20

The maximum volume of air that can be held in the lungs.

Question 21

Define VO2 MAX

Answer 21

The maximum volume of O2 that can be taken in and used in one minute.

Question 22

State the short term effects of exercise on the respiratory system

Answer 22

1. Increased breathing rate
2. Increased tidal volume

Question 23

State the long term effects of exercise on the respiratory system

Answer 23

1. Increased vital capacity
2. Increased number of alveoli
3. Increased lung capacity and volume
4. Increased tidal volume
5. Increased minute ventilation
6. Improved oxygen debt tolerance
7. Delay build up of lactic acid

Question 24

Label the compentents of the respiratory system

Answer 24

1. Nose/ Nasal cavity
2. Mouth/ Oral cavity
3. Larynx
4. Lung
5. Right bronchi
6. Diaphragm
7. Pharynx
8. Trachea
9. Left bronchi
10. Bronchiole
11. Alveoli